Résumés Année 1997

"Molecular Tectonics III : The Simultaneous Use of H-Bonding and Charge-Charge Interactions For the Self-Assembly of Fumaric Acid and Cyclic Bisamidinium Into One- and Two- Dimensional Molecular Networks"

Abstract : Self-assembling of complementary dianionic and dicationic tetrahydrogen bond donors and acceptors leading to a- and b-networks in the solid state was achieved using both directionally controlled hydrogen bonding and ion pairing electrostatic interactions.

Abstract : Whereas diprotonated 1 (1,2-Bis(2'-tetrahydropyrimidyl)ethane) forms a discrete exobinuclear complex with a dihapto mode of hydrogen bonding with 4-methylbenzoate anion 2- in the solid state, with 4,4'-biphenyldicarboxylate 3 2- an a-network composed of 1-2H+ dication and 32- dianion interconnected through strong hydrogen bonds and arranged in an alternating manner was obtained. The interconnection of the linear chains by water molecules affords a b-network.

"Molecular Tectonics V : Molecular Recognition in the Formation of Molecular Networks Based on Hydrogen Bonding and Electrostatic Interactions"

Abstract : The formation of a-molecular networks based on dihapto mode of H-bonding was investigated in the solid state using bis-cyclic amidinium dications and acetylenedicarboxylate dianion. It has been demonstrated that the formation of networks depends strongly on the structure of the components. A proper disposition of H-bond donor and acceptor sites indeed leads to the formation of infinite molecular assemblies in the crystalline phase.

Abstract : Benzene di- and tri-amidines 2 and 3 were prepared by treatment with HCl and NH3 of 1,4-dicyanobenzene and 1,3,5-tricyanobenzene, respectively. The cyclic analogue 4 was synthesised at 140 °C by mixing the mono tosylate salt of 1,3-propanediamine with 1,4-dicyanobenzene. The solid state structure of the hydrochloride salt of the latter (4-2HCl) was analyzed.

Abstract : An hollow molecular module (koiland) based on the double fusion of two p-allylcalix[4]arenes by two silicon atoms was obtained. The self-assembly of koilands into an a-network (koilate) based on the connection of koilands by linear molecular connectors was achieved in the solid state and characterised by X-ray analysis.

"Design and Synthesis of Porphyrines Bearing Catechols"

Abstract : Th e synthesis of meso-tetraarylporphyrines bearing 1-4 catechoylamid groups was achieved. Among the four new compounds prepared, the structure of the disubstituted ligand was elucidated in the solid state by an X-ray analysis.

Abstract : The synthesis of new macrocyclic ligands based on 2,2'-bipyridine unites interconnected at the 4 and 4' positions by alkyl chains was achieved. Homobinuclear RuII complexes were formed and the solid state structure of one of the diastereoisomers was investigated by X-ray analysis.

"Design, Synthesis and Structural analysis of Exoditopic Macrocyclic Ligands Based On Bipyridine Units"

Abstract : The synthesis of new unsymmetrical and symmetrical macrocycles based on 2,2'-bipyridine units bearing two or four phenyl groups at the 6 and 6' positions was achieved by an oxidative coupling reaction using 1,2-dibromoethane and organolithium derivatives of bipyridine. Among all new compounds prepared, two of them were structurally analysed in the solid state by X-ray diffraction.

"Multicavitands V : Synthesis and X-ray Analysis of Unsymmetrical Linear Koilands Based on the Double Fusion of two Different Calix[4]arenes by two Silicon Atoms"

Abstract : Unsymmetrical hollow molecular modules possessing two cavities oriented divergently were prepared by fusing two different calix[4]arene derivatives with two silicon atoms. Several of the compounds obtained were characterised by X-ray analysis.

Abstract : Upon treatment of the macrocycli c compound 1 bearing two catecholate moieties with equimolar amounts of B(OH)3 and aqueous NH3 in a H2O-EtOH mixture, the ammonium inclusion complex 2 was obtained exclusively. The latter was studied both in solution and in the solid state. The following selectivity sequence NH4+>Na+>Cs+ in CD3OD solution was obtained. Furthermore, the ammonium ion complex 2 was found to be more stable than the ([222], NH4+) complex by at least 3 orders of magnitude.

"Borocryptands : Synthesis and Strctural Analysis of a Lithium Borocryptate"

Abstract : A new lithium receptor based on the combination of the [11] macrocyclic core and two catechol units was designed and prepared. The binding ability of the ligand towards boron and lithium was demonstrated in solution by NMR and in the solid sta te by an X-ray analysis o f the lithiumborocryptate.

"Synthesis and Structural Analysis of a Exo-ditopic Macrocyclic Ligand Bearing 2,2'- bipyridine Units Interconnected by Silane Spacers and of its Binuclear Ruthenium Complex"

Abstract : The synthesis and structural analysis of a macrocyclic exo-ditopic ligand bearing two 2,2'-bipyridine units interconnected at the 4 and 4' positions by two -(CH2)2Si(CH2)2- spacers and of its acyclic analogue was achieved. For both compounds ruthenium homobinuclear complexes were prepared. In the case of the complex obtained with the cyclic ligand, both diastereoisomers were separated and the structure of the meso form was elucidated by X-ray analysis.